1. Field of the Invention
The present invention relates to in-vehicle navigation systems that periodically acquire information while parking with an engine-off, in which a battery run-out is prevented.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2001-227963 relates to a navigation system which is started for a predetermined period of time at predetermined intervals to receive information. This function is performed even when parked with the engine off and accessories in a power-off state so that the latest traffic information can be utilized immediately upon start-up of the navigation system via operation of an engine start-up key. The reception of the traffic information is performed only if a monitored battery level exceeds or equals a predetermined threshold level.